Vibrationally Induced Magnetism in Supramolecular Aggregates

Magnetic phenomena in chemistry and condensed matter physics are considered to be associated with low temperatures. That a magnetic state or order is stable below a critical temperature as well as becoming stronger the lower the temperature is a nearly unquestioned paradigm. It is, therefore, surprising that recent experimental observations made on supramolecular aggregates suggest that, for instance, the magnetic coercivity may increase with an increasing temperature and the chiral-induced spin selectivity effect may be enhanced. Here, a mechanism for vibrationally stabilized magnetism is proposed, and a theoretical model is introduced with which the qualitative aspects of the recent experimental findings can be explained. It is argued that anharmonic vibrations, which become increasingly occupied with an increasing temperature, enable nuclear vibrations to both stabilize and sustain magnetic states. The theoretical proposal, hence, pertains to structures without inversion and/or reflection symmetries, for instance, chiral molecules and crystals.

Automated summary

Magnetic phenomena in chemistry and condensed matter physics are usually associated with low temperatures. However, recent experimental observations on supramolecular aggregates suggest a surprising increase in magnetic coercivity with increasing temperature and enhancement of the chiral-induced spin selectivity effect. A proposed mechanism for vibrationally stabilized magnetism, along with a theoretical model, can explain the qualitative aspects of these experimental findings. The proposal argues that anharmonic vibrations, which become more pronounced at higher temperatures, can stabilize and sustain magnetic states, particularly in structures without inversion and/or reflection symmetries, such as chiral molecules and crystals.